Process for the preparation of modified emulsion polymers with oligourethane salt

ABSTRACT

A process is provided for the preparation of aqueous dispersions of polymers of olefinically unsaturated monomers in the presence of emulsifiers capable of forming free radicals which emulsifiers contain urethane groups, characterized in that 5 TO 95 PERCENT BY WEIGHT OF AT LEAST ONE POLYMERIZABLE OLEFINICALLY UNSATURATED MONOMER IS POLYMERIZED IN THE PRESENCE OF 5 TO 95 PERCENT BY WEIGHT OF ONE OR MORE OLIGOURETHANE SALTS HAVING AN AVERAGE MOLECULAR WEIGHT OF 1,500 TO 20,000 (PREFERABLY 2,000 TO 10,000) AND A TENSILE STRENGTH OF LESS THAN 20 KG WT/CM2, WHICH SALTS HAVE BEEN PREPARED FROM WATERINSOLUBLE OLIGOHYDROXY COMPOUNDS HAVING A MOLECULAR WEIGHT OF 400 TO 5,000.

United States Patent Reiff et a1.

[54] PROCESS FOR THE PREPARATION OF MODIFIED EMULSION POLYMERS WITHOLIGOURETIIANE SALT [72] Inventors: Helmut Reiff, Cologne-Flittard;Dieter Dieterich; Frank Wingler, both of Leverkusen, all of Germany [73]Assignee: Farbenfabriken Bayer Aktiengesellschait, Leverkusen, Germany[22] Filed: Oct. 21, 1970 [21] Appl.N0.: 82,796

[30] Foreign Application Priority Data Oct. 23, 1969 Germany ..P 19 53349.4

[52] US. Cl....260/29.6 NR, 1 17/161 KP, 260/2.5 R, 260/8, 260/17.3,260/17.4 R, 260/23 EM,

260/28, 260/29.4 UA, 260/29.7 NR,

[51] Int. Cl. ..C08f 45/24 [58] Field of Search .260/29.6 R, 29.6 NR,206 MN, 260/29.60 L, 29.7 R, 29.7 NR, 77.5 QU

[56] References Cited UNITED STATES PATENTS 3,249,654 5/ 1966 von Boninet a1 ..260/874 [1.51 3,684,759 1 Aug. 15,1972

3,388,087 6/ 1968 Dieterich et al. ..260/77.5 QU 3,427,192 2/ 1969Bolinger ..260/29.6 NR 3,479,310 11/1969 Dieterich et al....260/29.6 NR3,491,050 l/ 1970 Keberle et al ..260/77.5 QU 3,491,051 l/1970 Elkin et:al ..260/29.6 NR 3,539,483 1 H1970 Keberle et a1 ..260/29.6 NR

Primary Examiner-Harold D. Anderson Att0rney-Robert A. Gerlach andSylvia Gosztonyi [57] ABSTRACT A process is provided for the preparationof aqueous dispersions of polymers of olefinically unsaturated monomersin the presence of emulsifiers capable of forming free radicals whichemulsifiers contain urethane groups, characterized in that 5 to 95percent by weight of at least one polymerizable olefinically unsaturatedmonomer is polymerized in the presence of 5 to 95 percent by weight ofone or more oligourethane salts having an average molecular weight of1,500 to 20,000 (preferably 2,000 to 10,000) and a tensile strength ofless than 20 kg wt/cm which salts have been prepared fromwater-insoluble oligohydroxy compounds having a molecular weight of 400to 5,000.

17 Claims, No Drawings PROCESS FOR THE PREPARATION OF MODIFIED EMULSIONPOLYMERS WITH OLIGOURETHANE SALT The preparation of polymers andcopolymers from vinyl monomers by emulsion polymerization is alreadyknown. In such processes, one or more vinyl monomers are emulsified inwater and polymerization is initiated by the addition of starters.Emulsifiers are necessary in order to emulsify the hydrophobic monomersand insure that the latex formed when polymerization is completed isstable. The substances used as emulsifiers are soap-like, low molecularweight compounds which have a hydrophilic center in addition to ahydrophobic radical. Such compounds are disadvantageous because they arevery hydrophilic, they often have poor compatibility with the polymerformed and because of very low molecular weights which generally rangebetween about 100 and 300 they tend to migrate. For these reasons thefilms and the coatings obtained by drying emulsion polymer latices aremicroheterogeneous and have poor resistance to water.

Some improvement has been achieved by using monomers which enablepolymers containing ionic centers to be formed such as acrylic acid,vinyl sulphonic acid and dialkyl aminoalkyl acrylates. The latices thusformed are stable even in the absence of emulsifiers. Nevertheless, theuse of emulsifiers cannot be dispensed with even in these cases sincethe monomers must be emulsified before polymerization. The addition ofthe usual emulsifiers invariably involves the introduction of lowmolecular weight, extractable materials into the polymer which areundesirable and detrimental to the properties of the polymer and whichremain unchanged in the polymer during and after the secondaryreactions.

It is also known that polymerization may be carried out in the presenceof high molecular weight cationic polyurethanes which act as emulsifiersand which contain quaternary ammonium or tertiary sulphonium groups.However, these polyurethanes are high molecular weight elastic syntheticresins and, as such, have tensile strengths of 100 to 300 kg wt/cm Thedispersions are prepared by a special process in which a high molecularweight, predominantly linear polyurethane is alkylated in an organicsolvent, after which the organic solvent is distilled off or replaced bywater. Although such a process entails considerable time and expense,the emulsifying effect achieved is nevertheless often unsatisfactorybecause the surface tension of the aqueous sols and dispersions obtainedis often greater than 40 dynes/cm (see German Pat. Nos. 1,184,946;1,178,586 and German document laid open to inspection No. 1,544,892).Furthermore, high molecular weight anionic polyurethanes prepared frombischlorocarbonic acid esters and diamino sulphonic acids which havebeen proposed as emulsifiers do not have a specifically hydrophobicsegment so that their emulsifying effect is low compared to styrene,vinyl chloride or butyl acrylate, for example. Moreover, they areunsuitable for use in emulsion polymerization for economic reasons (seeGerman Auslegeschrift No. 1,044,404).

Lastly, interfacial surface active urethane salts which have beenprepared by reacting hydrophobic higher alkyl isocyanates with, forexample, salts of aminocarboxylic acid or sulphonic acids are known.These salts are monoor di-urethanes which contain the usual structure ofemulsifiers and have molecular weights below 600 [see E. Ulsperger,Tenside 3, l 1966)].

1t is therefore an object of this invention to provide stable aqueouspolymer dispersions and a method for preparing them which are devoid ofthe foregoing disadvantages.

Another object of this invention is to provide stable aqueous polymerdispersions and a method for preparing them which does not require theuse of anemulsifier.

Still another object of this invention is to provide stable dispersionsof modified polymers obtained by the emulsion polymerization ofolefinically unsaturated monomers.

A still further object of this invention is to provide stable aqueousdispersions of polymers which have improved elasticity and abrasionresistance as well as a reduced tendency to swell in organic solvents.

The foregoing objects and others which will become apparent from thefollowing description are accomplished in accordance with thisinvention, generally speaking, by providing a process for thepreparation of aqueous dispersions of polymers from olefinicallyunsaturated monomers in the presence of radical-forming emulsifierswhich contain urethane groups, characterized in that from about 5 toabout 95 percent by weight of at least one polymerizable olefinicallyunsaturated monomer is polymerized in the presence of from about 5 toabout 95 percent by weight of one or more oligourethane salts which havean average molecular weight of from about 1,500 to about 20,000(preferably 2000 to 10,000) and a tensile-strength of less than about 20kg wtlcm The oligourethane salts are prepared from oligohydroxycompounds which are insoluble in water and have molecular weights offrom about 400 to about 5,000.

The problems involved in the preparation of stable dispersions ofmodified polymers from olefinically unsaturated monomers are solved byusing oligourethane salts prepared from oligohydroxy compounds which areinsoluble in water as emulsifiers for the emulsion polymerization ofolefinically unsaturated monomers. The emulsifiers may be usedsatisfactorily even in high concentrations without adversely affectingthe polymers formed. In many cases, the use of these new emulsifierseven results in an improvement of the properties of the polymers, e.g.,an improvement in the elasticity and the abrasion resistance, as well asa reduction of the tendency of the polymers to swell in organicsolvents. The oligourethane salts not only serve as emulsifiers but alsobring about a modification of the olefin polymer.

As oligourethane is meant compounds which contain a statistical averageof at least two and not more than about 10 urethane groups. 1f ureagroups are present as well as urethane groups, the total of the twogroups should not be more than about 10 and products which contain threeto eight such groups are preferred. The average molecular weight of theoligourethanes is at least about 1,500 and at the most about 20,000 andmolecular weights of between 2,000 and 10,000 are preferred.Accordingly, oligourethanes are not polyurethane macromolecules and theydo not have the character of synthetic resins. The tensile strength ofthe oligourethanes in the dry state is in all cases less than about 20kg wt/cm and preferably below about 5 kg wt/cm In most cases,oligourethanes are plastic products which have a high viscosity butwhich do not form self-supporting films.

1. Any compound containing at least two groups reactive with isocyanategroups may be used to prepare the oligourethane salts of this invention.Some such suitable materials include compounds that contain terminalhydroxyl groups and have molecular weights of between about 400 andabout 5,000, preferably polyethers, polyacetals, polythioethers,polyesters, polyether esters, polyamides and polyester amides.Hydrocarbons containing hydroxyl groups such as polybutadiene withterminal hydroxyl groups are also suitable.

As polyethers one may employ, for example, the polymerization productsof styrene oxide, ethylene oxide, propylene oxide, tetrahydrofuran,butylene oxide, epichlorohydrin, their copolymerization or graftpolymerization products and the like, as well as the polyethers obtainedby condensation of polyhydric alcohols or mixtures thereof and by thealkoxylation of polyhydric alcohols, amines, polyamines and aminoalcohols. lsotactic polypropylene glycol may also be used. Productswhich have a high alkylene oxide content are unsuitable if they giverise to water-soluble polyurethanes.

As polyacetals one may employ, for example, compounds prepared fromglycols such as diethylene glycol, triethylene glycol,4,4'-dihydroxy-ethoxydiphenyldimethyl-methane, hexanediol andformaldehyde. Suitable polyacetals may also be prepared by thepolymerization of cyclic acetals.

Some polythioethers which are particularly suitable are the condensationproducts of thiodiglycol with itself and/or with other glycols,dicarboxylic acids, formaldehyde, aminocarboxylic acids or aminoalcohols. Depending on the coreactant employed, the products may bemixed polythioethers, polythioether esters or polythioether esteramides. Polyhydroxy compounds of this type may also be used in theiralkylated form or in admixture with alkylating agents.

As polyesters, polyester amides and polyamides one may use thepredominantly linear or branched condensates obtained from polyvalentsaturated and unsaturated carboxylic acids or their anhydrides andpolyvalent saturated and unsaturated alcohols, amino alcohols, diamines,polyamines and mixtures thereof and also e.g., polyterephthalates orpolycarbonates. Polyesters of lactones, e.g., of e-caprolactone or ofhydroxycarboxylic acids may also be used. The polyesters may containhydroxyl or carboxyl end groups. The alcohol reactants used in thesynthesis of these materials may also consist either entirely or partlyof higher molecular weight polymers or condensates, e.g., polyethers,polyacetals and polyoxymethylenes. Unsaturated polyesters may be graftedwith vinyl monomers.

Some suitable components for the synthesis of polyesters include, forexample, ethylene glycol, diethylene glycol, triethylene glycol,tetraethylene glycol, 1,2-propylene glycol, l,3-propylene glycol,butane-2,3-diol, butane-l,4-diol, pentane-l,5-diol, hexane-l ,6-diol,2,2-dimethylpropanel ,3-diol, cyclohexane dimethanol, quinitol,glycerol, trimethylol propane, hexanetriol, pentaerythritol, butenediol,bishydroxyethyldiane, succinic acid, glutaric acid, adipic acid, subericacid, phthalic acid, isophthalic acid, terephthalic acid, dimethylterephthalate, bis-glycol terephthalate, maleic acid anhydride, fumaricacid, 6- hydroxy-caproic acid, 4-hydroxybenzoic acid, trimellitic acidand the like and mixtures thereof.

Polyhydroxy compounds which contain urethane or urea groups as well asoptionally modified natural polyols such as castor oil or carbohydratesmay also be used.

In principle, any polyhydroxy compounds which contain basic nitrogenatoms may be used, e.g., polyalkoxylated primary amines or polyesters ofpolythioethers which contain alkyl diethanolamine by condensation.Compounds which contain reactive halogen atoms may also be incorporatedby condensation, e.g., glycerol-achlorohydrin. Such compounds may alsobe present in alkylated, i.e., onium form. Polyesters which havebuilt-in sulphonate or carboxylate groups as described, for example, inUS. Pat. application Ser. No. 869,949, filed on Oct. 27, 1969, nowabandoned, may also be used. Any of the active hydrogen containingcompounds suggested in US. Pat. No. 3,201,372 may be used. Mixtures ofvarious polyhydroxy compounds may be used to vary the lyophilic orhydrophobic character and mechanical properties of the products of theprocess.

2. Any aromatic, aliphatic and cycloaliphatic diisocyanates may be usedto prepare the oligourethanes of this invention including, e.g.,1,5-naphthylene diisocyanate, 4,4-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, diand tetraalkyldiphenylmethanediisocyanate, 4,4'-dibenzyl diisocyanate, l,3-phenylene diisocyanate,l,4-phenylene diisocyanate, the isomers of tolylene diisocyanate,optionally as mixtures, l-methyl-2,4-diisocyanatocyclohexane, 1,6-diisocyanato-2,2 ,4- trimethylhexane, cyclohexanel ,4-diisocyanate,dicyclohexylmethane diisocyanate, l-isocyanatomethyl-3-isocyanatol ,5,S-trimethylcyclohexane, chlorinated and brominated diisocyanates,diisocyanates which contain phosphorus,4,4'-diisocyanatophenyl-perfluoroethane, tetramethoxybutane-l ,4-diisocyanate, butanel ,4-diisocyanate, hexane-l ,6- diisocyanate,ethylene diisocyanate, pxylylene diisocyanate, m-xylylene diisocyanateand the hydrogenation products of the aromatic diisocyanates mentionedabove. Urethane dior tri-isocyanates and biuret dior tri-isocyanates mayalso be used, e.g., addition products of hexanel,6-diisocyanato,xylylene-l ,3- diisocyanate or 1-methyl-2,4-diisocyanato-cyclohexanewith water or amines or polyalcohols; also isocyanates which containionic groups and which may be prepared, for example, by the addition ofisocyanates which contain reactive halogen atoms to ditertiary andpolytertiary amines, bis-isocyanatoethylphthalate, diisocyanates whichcontain reactive halogens atoms such asl-chloromethylphenyl-2,4-diisocyanate,lbromomethylphenyl-2,6-diisocyanate or 3,3-bischloromethylether-4,4'-diphenyl diisocyanate.

Any of the isocyanates suggested in US. Pat. No. 3,350,362 may also beused and aliphatic and araliphatic diisocyanates and the isomers oftolylene diisocyanate are particularly preferred.

. 3. Any glycols, amino alcohols or diamines containing salt groups orgroups which are converted into salt groups by simple alkylation orneutralization reactions (potential salt groups) may be used to preparethe oligourethane salts of this invention. These include:

a. Glycols or diamines which contain tertiary amino groups, e.g., mon-,bisor poly-alkoxylated aliphatic, cycloaliphatic, aromatic orheterocyclic primary amines such as N-methyl diethanolamine, N-ethyldiethanolamine, N-propyl diethanolamine, N-isopropyl diethanolamine,N-butyl diethanolamine, N-isobutyl diethanolamine, N-oleyldiethanolamine, N-stearyl diethanolamine, ethoxylated amine of coconutoil, N- allyl diethanolamine, N-methyl-diisopropanolamine,N-ethyl-diisopropanolamine, N-propyL diisopropanolamine,N-butyl-diisopropanolamine, N- cyclohexyldiisopropanolamine,N,N-diethoxyaniline, N,N-diethoxytoluidine, N,N-diethoxy-aaminopyridine,N,N'-diethoxypiperazine, dimethyl-bisethoxy-hydrazine, N,N '-bis-(b-hydroxyethyl )-N,N'- diethyl-hexahydro-p-phenylene diamine,N-b-hydroxyethyl piperazine, polyalkoxylated amines such as propoxylatedmethyl diethanolamine; also compounds such asN-methyl-N,N-bis-g-aminopropylamine,N-(gaminopropyl)-N,N'-dimethylethylene diamine, N-(gaminopropyl)-N-methyl ethanolamine,N,N'-bis-(gaminopropyl)-N,N'dimethylethylene diamine, N,N'-bis-(g-aminopropyl)-piperazine, N-(b-aminoethyl)- piperazine,N,N'-bis-ethoxypropylene diamine, 2,6- diaminopyridine,diethanolamine-acetamide, diethanolamine-propionamide,N,N-bis-ethoxyphenylthiosemicarbazide,N,N-bis-ethoxymethylsemicarbazide,p,p'-bis-aminomethyl-dibenzylmethylamine, 2,6- diaminopyridine and2-methy1-3-aminopropylaminoethanol-( l b. Glycols or diamines whichcontain sulphide groups such as thiodiglycol or bis-2-aminoethylsulphide.

c. Glycols or diamines which contain quatemizable halogen atoms or RSOgroups, for example glycerola-chlorohydrin, glycerol monotosylate,pentaerythritolbis-benzene sulphate, glycerol monomethane sulphonate,addition products of diethanolamine or of chloromethylated aromaticisocyanates or aliphatic haloisocyanates such as N,N-bis-hydroxyethyl-N'mchloromethylphenyl urea, N-hydroxyethyl-N'- chlorohexyl urea, glycerolmonochloroethyl urethane, bromoacetyl dipropylene triamine orchloroacetic acid diethanolamide.

d. Hydroxy or aminocarboxylic acids such as glyceric acid,dihydroxymaleic acid, dihydroxyfumaric acid, tartaric acid, citric acid,serine omithine, histidine, lysine, proline, aspartic acid, glutamicacid, oxaluric acid, anilidoacetic acid, anthranilic. acid, 2-ethylaminobenzoic acid, 3-aminobenzoic acid, 4- aminobenzoic acid,N-phenylaminoacetic acid, 3,4- diaminobenzoic acid,S-aminobenzene-dicarboxylic acid or Z-aminQethyI-aminoethane carboxylicacid.

e. l-lydroxy or aminosulphonic acids, such as l,4-butanediol-Z-sulphonicacid, taurine, 4,6- diaminobenzene-disulphonic acid-( 1,3), 2,4-diaminotoluene-sulphonic acid-( 5 4,4- diarninodiphenyl-disulphonicacid-( 2,2), 2-

aminophenol-sulphonic acid-(4), 4,4'-diamino-diphen- 6 ylether-sulphonic acid-(2), Z-aminoanisole-N- methane sulphonic acid,Z-aminodiphenylamine sulphonic acid, ethylene glycol sulphonic acid,2,4- diaminobenzene sulphonic acid or 6-aminohexylaminopropane sulphonicacid.

f. Hydroxy or aminophosphinic acids, hydroxy or aminophosphonic acids,hydroxy or aminophosphorous acid esters or hydroxy or aminophosphoricacid esters, e.g., bis-(a-hydroxyisopropyl)-phosphinic acid,hydroxyalkane phosphonic acid, bis-glycol esters of phosphorous acid,bis-glycol ester of phosphoric acid or bis-propylene glycol ester ofphosphoric acid. 4. Any chain breaking monoisocyanates including thoselisted in US. Pat. No. 3,350,362 such as methyl isocyanate, ethylisocyanate, phenyl isocyanate, methoxymethyl isocyanate, 2-chloroethylisocyanate, 6-chlorohexyl isocyanate, m-chloromethylphenyl isocyanateand the like may be used in the preparation of the oligourethane of thisinvention.

5. Any chain breaking compounds which are monofunctional with respect toisocyanates and which contain (potential) salt groups may be used in thepreparation of the oligourethanes of this invention ineluding:

a. Tertiary amines, e.g., N,N-dimethyl ethanolamine, N,N-diethylethanolamine, l-dimethylaminopropanol- (2), N'ethoxymorpholine,N-methyl-N-b-hydroxyethylaniline, N-ethoxypiperidine,a-hydroxyethylpyridine, g-hydroxyethylquinoline, N,N-dimethylhydrazine,N,N-dimethylethylene diamine, ldiethylamino-4-aminopentane,a-aminopyridine, 3- amino-N-ethylcarbazole, N,N-dimethylpropylenediamine, N-aminopropyl piperidine, N-aminopropyl morpholine,N-aminopropyl ethylene imine, 1,3-bispiperidino-Z-aminopropane ordimethylaminopropyl urea.

b. Sulphides, e.g., Z-hydroxyethyl methyl sulphide.

c. Alkylating agents such as 2-chloroethanol, 2- bromoethanol,chloroacetamide, clhloroacetic acid and bromoacetic acid.

d. Hydroxy or aminocarboxylic acids which have a chain breaking action,e.g., glycollic acid, lactic acid, glycine, aand b-alanine,o-aminocaproic acid, 4- aminobutyric acid, sarcosine, 2-hydroxy-ethanolsulphonic acid, sulphanilic acid, taurine, methyltaurine, butyltaurine,arninomethane sulphonic acid, 3- aminobenzoic acid, 4-aminobenzoic acid,phenol sulphonic acid-(3), phenol disulphonic acid-(2,4), aminoethanolsulphuric acid monoester, 3- arninopropane sulphonic acid, 4-aminobutanesulphonic acid, 3-methylaminopropane sulphonic acid, succinic acidmono-2-hydroxyethyl amide, dihydroxymaleic acid monoamide, tartaric acidmonoureide, citric acid monoamide and citric acid diamide, citric acidmonoureide and citric acid diureide, tartaric acid amide, asparagine,glutamine, aspartic acid monoureide, glutamic acid monoureide,ureidosuccinic acid, acetamide-C-sulphonic acid, acetylurea-C-sulphonicacid, acetylguanidine-C-sulphonic acid, propionyl urea-a-sulphonic acid,propionamide-a-sulphonic acid, butyramide-a-sulphonic acid,isobutyramide-asulphonic acid, acetoguanamine sulphonic acid, N-methyl-asparagine, N-methyl-aspartic acid ureide, N-hydroxyethyl-asparagine and N-hydroxyethyl-aspanic acid ureide. Additionproducts of amino amides or amino ureides with a,b-unsaturatedcarboxylic acids, addition products of aminocarboxylic acids ofaminosulphonic acids with a,b-unsaturated carboxylic acid amides orcarboxylic acid ureides, N-carbonamidomethyl glycine,N-carbonamidomethyl anthranilic acid, carboxymethylaminoacetyl urea,addition products of sultones and b-lactones such as bpropiolactone withureas and carbonamides, such as 3- ureidopropane sulphonic acid,3-ureidobutane sulphonic acid, 2-ureidopropionic acid andadimethylamino-b-hydroxypropionamide.

6. Any chain breaking agents which do not have the character of(potential) salts may be used in the preparation of the oligourethane ofthis invention including methanol, ethanol, isopropanol, glycolmonomethyl ether, diethylene glycol monomethyl ether, dibutyl amine,acetic acid, urea, thiourea, sulphamide, methyl urea, oxamide, ethyleneurea, dicyandiamide, glycollic acid amide, glycine amide, hydrazineacetamide, 2-hydroxyethyl urea, 2-hydroxyisopropyl urea, succinic acidamide, succinic acid mono-ureide, 6-aminocaproic acid amide, l1-aminoundecanoic acid amide, phthalic acid monoamide, glycide,3-ethyl-3-hydroxymethyloxetane, 3- methyl-3-hydroxymethyloxetane andglycerol-1,3- dimethyl ether.

7. Any monofunctional alkylating agents which will convert the basicreactants into the salt form may be used including, for example, methylchloride, methyl bromide, methyl iodide, ethyl bromide, propyl bromide,butyl bromide, dimethyl sulphate, diethyl sulphate, methyl chloromethylether, methyl-1,2- dichloroethyl ether, ethylchloromethyl ether, benzylchloride, benzyl bromide, p-chlorobenzyl chloride, trichlorobenzylchloride, p-nitrobenzyl chloride, ethylene chlorohydrin, ethylenebromohydrin, epichlorohydrin, ethylene oxide, propylene oxide, styreneoxide, benzene sulphonic acid ester, toluene sulphonic acid ester,naphthalene sulphonic acid ester, w-bromoacetophenone,dinitrochlorobenzene, dchloropentenamide, chloroacetic acid and estersand amides thereof, chloromethyl dimethylethoxy silane,pentamethylchloromethyldisiloxane, pentamethylbromomethyldisiloxane,glycol monobromoacetic acid esters, glycerol monochloroacetates,bromoethyl isocyanate, chloromethyl naphthalene, 3-methyl-3-hydroxymethyl, oxetane-methane sulphonate, phenyl ethyl bromide,p-2-bromoethyl-benzoic acid, 5- chloromethylfuran-Z-carboxylic acid,dichloroisopropyl ester of ethylphosphonic acid, bromoethyl ester ofacetic acid, chloroacetamide, bromoacetamide, N-methyl-chloroacetamide,bbromopropionic acid amide, a-chloropropionic acid amide,a-bromopropionic acid amide, a-bromoisobutyric acid amide,m-chloromethylbenzamide, pchloromethylbenzamide,p-chloromethylbenzamide, 4- chloromethyl phthalic acid diamide,a-bromosuccinic acid diamide, 2-chloro-4,6-diamino-s-triazine, 2-chloro-4-methoxy-6-amino-s-triazine, a-methylsulphonylhydroxy succinicacid diamide, ethylsulphonylhydroxyacetamide, chloroacetyl urea, propanesultone, butane sultone, and epoxides are used in combination with waterand/or a salt as quatemizing agent.

Polyfunctional alkylating agents are also suitable e.g.,1,4-dibromobutane, p-xylylene dichloride, 1,3-

dimethy1-4,6-bis-chloromethylbenzene, methylene-bischloroacetarnide,hexamethylene-bis-bromoethyl urethane, addition products of 2 to 3 molsof chloroacetamide with di or tri-isocyanate.

Trimethylamine, triethylamine, triethanolamine, dimethylaminoethanol,N-methyl-diethanolamine, pyridine, quinoline and N-dimethylaminopropyldiethanolamine are mentioned as examples of tertiary amines which aresuitable for quaternization.

8. Any acids may be used that are suitable for the salt formation oftertiary amines, such as hydrochloric acid, fluoboric acid,amidosulphonic acid, phosphoric acid and derivatives thereof, tartaricacid, oxalic acid, lactic acid, acetic acid, acrylic acid, sulphurousacid, sulphuric acid, hydrobromic acid, hydrofluoric acid, phosphorousacid and hypophosphorous acid.

9. Any bases may be used that are suitable for salt formation ofcarboxylic acids or of sulphonic acids including, for example,

a. Organic bases such as monofunctional primary, secondary and tertiaryamines, for example methylamine, diethylamine, ethylamine,tributylamine, pyridine, aniline, toluidine, alkoxylated amines such asethanolarnine, diethanolamine, triethanolamine, methyl diethanolamine,dimethylaminoethanol, oleyl diethanolamine and polyfunctional polyaminesin which the individual amino groups may differ in their basicity, e.g.,the polyamines obtained by hydrogenation of addition products ofacrylonitrile with primary and secondary amines or peralkylated orpartially alkylated polyamines such as N,N-dimethyl ethylene diamine, orcompounds such as a-aminopyridine or N,N-dimethylhydrazine;

b. Inorganic bases or compounds which are basic in a reaction medium orwhich split off bases, such as ammonia, monovalent metal hydroxides,metal carbonates and metal oxides such as sodium hydroxide or potassiumhydroxide.

The oligourethane salts of this invention are prepared in a known mannerby reacting compounds which contain terminal hydroxyl groups and whichhave a molecular weight of between 400 and 5,000, preferably between 600and 3,000 from group 1 with diisocyanates from group 2 and optionallywith chain lengthening agents from groups 3 (a) to (f) at temperaturesof between about 20 C and about 160 C (preferably between about 50 andabout C.). The chain lengthening agent may be added simultaneously orsubsequently.

The following fundamental distinctions are made with respect to thestructure of the oligourethanes which are to be used in the practice ofthis invention:

A. oligourethanes which contain terminal hydroxyl or primary resp.secondary amino groups and in which an NCO/OH ratio of 0.4 to 0.9 andpreferably 0.5 to 0.8 is observed. The terminal hydroxyl or amino groupsmay then, if desired, be reacted with monofunctional isocyanates fromgroup 4.

B. oligourethanes which contain terminal groups other than hydroxyl orprimary resp. secondary amino groups. An NCO/OH ratio of between 1.1 and2, preferably between 1.2 to 1.7 should be observed. In that case, thereare generally at least two NCO groups per each oligourethane molecule,which corresponds to a free NCO group content of 0.3 to 20 percent byweight (preferably 0.8 to 10 percent by weight). This prepolymer isreacted with compounds of groups and 6 which generally act asmonofunctional chain breaking agents with respect to the isocyanate endgroups. Therefore, the compounds mentioned in groups 5 and 6 shouldreact mainly with chain breaking in order that the average molecularweight will not exceed 20,000 and will preferably be between 2000 and10,000. The oligourethanes thus prepared do not contain contain terminalNCO-groups.

If the components from groups 3 and 5 are introduced in the synthesis ofthe oligourethanes in the form of salts, for example as methyl sulphateor, in the case of anionic components, in the form of the alkali metalor amine salts, the oligourethane salts are obtained directly after thecompleted synthesis reaction and are ready to use in the practice of theinvention. If, on the other hand, the oligourethanes only containpotential salt groups at the stage of molecular synthesis, for exampletertiary amino nitrogen or three carboxyl groups, then theoligourethanes are modified with saltforming agents or quatemizingagents from groups 7, 8 or 9 after introduction of the end groups or atany time during the synthesis reaction. One may also use a combinationof various salt-forming and/or quatemizing agents and the potential saltgroups may be only partly neutralized or quaternized, if desired.

The oligourethane salts of this invention should have a salt groupcontent of from about 10 to about 400 milliequivalents percent (i.e.,from about 10 to about 400 milliequivalents per 100 g), and preferablyfrom about to about 200 milliequivalents percent. The ob servance ofthese limits insures good dispersability in water and a good emulsifyingeffect towards monomers.

The introduction of the chain breaking end groups into theoligourethanes synthesized as described under A or B is carried out attemperatures of between about 20 C and about 150 C. Temperatures ofbetween about 60 and about 120 C. are preferred. At higher reactiontemperatures there is a risk of incipient decomposition of thepolyurethane mass, whereas at lower temperatures the reaction mass isdifficult to stir. The reaction temperature chosen also depends on thereactivity of the compound added to the prepolymer to provide the endgroups. In any event, it is advisable to operate above the melting pointof the additive, which may be crystalline, in the event that thesolubility is insufficient.

The oligourethanes of this invention may contain salt groups havingdiverse chemical constitutions. The following groups are examples ofthose most commonly used:

The oligourethanes need not be in the finished salt form before thewater is added. Instead, these groups may be present as potentialgroups, i.e., in a form capable of salt formation. This is particularlyadvantageous if salt formation is effected by a simple neutralizationprocess in the presence of water. The following groups Since saltformation in an anhydrous medium is usually associated with a highincrease in viscosity, it may be advantageous if salt formation by theaddition of acids or bases is carried out only after the addition ofwater, particularly in the case of oligourethanes which are highlyviscous in any case.

Salt groups and groups capable of salt formation may also be presentsimultaneously.

A point which should be considered in the preparation of theoligourethanes of this invention is that the solvent-free melt should beeasy to handle in the usual mixing apparatus. Therefore, theoligourethane mass formed should preferably have a viscosity of lessthan about 1,500 poises and most preferably from about 50 to about 1,000poises at about C. Further, the viscosity may be lowered by the additionof small quantities of solvents such as dimethyl formamide, diethylformamide, ethanol, isopropanol, methyl ethyl ketone, ethylene glycol,diethylene glycol and their ethers and esters, if desired. The quantityof solvent thus introduced should not exceed about 10 percent by weightof the total oligourethane dispersion; preferably, however, only fromabout 0.2 to about 5 percent by weight should be employed. Nevertheless,the oligourethanes of this invention are preferably prepared without theuse of organic solvents. The viscosity of the oligourethane is, however,no essential feature of the process of the invention.

In the synthesis of cationic oligourethanes having built-in tertiaryamino groups, it is generally possible to dispense with the use of acatalyst for the isocyanate reaction. When synthesizing sulphoniumoligourethanes or oligourethanes which contain anionic groups, it isgenerally advantageous to use a catalyst. Any suitable catalysts may beused including particularly tertiary amines and organometallic compoundssuch as tributylamine diazabicyclooctane, pyridine, tin octoate,dibutyltin dilaurate, zinc octoate, cobalt naphthenate, iron acetylacetonate and any of those suggested in US. Pat. Nos. 3,201,372;2,948,928; 2,941,967; 2,948,691 and the like and mixtures thereof.

The oligourethanes of this invention can be adjusted to the requiredsolids content by the addition of water in aqueous dispersions or salts(which may be optically clear). The oligourethanes should contain nofree NCO groups and should have an average molecular weight of less thanabout 20,000 and preferably between about 2,000 and about 10,000.Although the average molecular weight is difficult to determine exactly,it can be assessed sufficiently accurately by end group determinationand osmometric measurements. In many cases, the approximate averagemolecular weight is obtained from the stoichiometric relationships ofthe reactants in the synthesis of the polyurethane.

Cationic and anionic oligourethane salts suitable for use in thepractice of this invention may also be prepared by the cationic oranionic modification of nonionic oligourethanes via addition reactions.Thus, for example, oligourethanes which contain unsaturated C C doublebonds can be modified to form polyelectrolytes by the addition of anycompound which contains at least one OH, SH, NHR or SCl group which iscapable of undergoing an addition reaction and another group which iscapable of salt formation, e.g.:

R I N'-/ (RzH or C C;-a1kyl), II, C O 011, S 03H or on P or acorresponding salt group.

Some examples of suitable compounds containing groups capable ofaddition reactions include thioglycollic acid, glycollic acid,b-chlorosulphenylpropionic acid, b-alanine-Na, lysine,dimethylaminoethanol, diethylaminoethylmercaptan, N,N-dimethylpropylenediamine, methyl-2-hydroxyethyl sulphide, ethyl-2-mercaptoethyl sulphide,taurine, N-methyltaurine, Z-mercaptoethyl sulphonic acid sodium,N,N-dimethylhydrazine, N,N- dimethylethylene diamine, sodium hydrogensulphite and the like.

Another method of modification consists in reacting oligourethanes withcyclic compounds which have three to seven ring members and whichcontain salttype groups or groups which are capable of salt formationafter ring opening, e.g., dicarboxylic acid anhydrides, disulphonic acidanhydrides, sulphocarboxylic acid anhydrides, sultones, lactones,epoxycarboxylic acids, epoxysulphonic acids, Ncarboxyglycine anhydride,carbyl sulphate and the like. This method of modification is describedin detail in US. Pat. No. 3,461,103.

The polymerization reaction of the olefinically unsaturated monomers iscarried out by the usual methods of emulsion polymerization in thepresence of the oligourethanes described above. The ratio ofpolymerizable olefinically unsaturated monomers to oligourethane saltsemployed in this method is from about to about 95 parts by weight,preferably 50 to 95 parts by weight, of polymerizable monomers to fromabout 95 to about 5 parts by weight, preferably 5 to 50 parts by weightof oligourethane. Another advantageous range is from about 5 to aboutparts by weight of monomer to from about 85 to about 95 parts by weightof oligourethane.

Any suitable olefinically unsaturated monomers may be polymerized in thepractice of this invention includmg:

a. a,b-Olefinically unsaturated monocarboxylic acids containing 3 to 5carbon atoms and their derivatives such as acrylic, methacrylic andcrotonic acid, acrylic and methacrylic acid amides, acrylonitrile andmethacrylonitrile, esters of acrylic and methacrylic acid, particularlythose with saturated monohydric aliphatic or cycloaliphatic alcoholswhich contain one to carbon atoms, such as esters of the above mentionedacids with methyl, ethyl, propyl, isopropyl, isobutyl, hexyl, octyl orstearyl alcohol, cyclohexanol, methylcyclohexanol or with benzylalcohol, phenol, cresol or furfuryl alcohol; monoesters ofa,bmonoolefinically unsaturated monocarboxylic acids having three tofour carbon atoms with divalent saturated aliphatic alcohols having twoto four carbon atoms, for example 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxyethylacrylate, 2-hydroxypropyl acrylate and 4-hydroxybutyl acrylate;aminoalkyl esters of acrylic and methacrylic acid, such as 2 arninoethyl(meth)acrylate hydrochloride, glycol diacrylate, glycol dimethacrylate,alkyl esters of acrylic or methacrylic acid, and glycerol trisacrylicesters of glycerol trismethacrylic esters.

b. a,b-Olefinically unsaturated dicarboxylic acidscontaining three tofive carbon atoms and their derivatives, such as fumaric acid, maleicacid, itaconic acid, monoand di-esters of the above mentioneddicarboxylic acids having one to 18 carbon atoms in the alcohol radicalsuch as dimethyl maleate, diethyl maleate, dibutyl maleate, monohexylmaleate and monocyclohexyl maleate.

c. Monoand di-esters of vinyl alcohol with carboxylic acids or withhydrohalic acids, vinyl ethers, vinyl ketones, vinyl amides, such asvinyl acetate, vinyl propionate, vinyl laurate, vinyl stearate, vinylbenzoate, chlorovinyl acetate, divinyl adipate, vinyl chloride,vinylidene chloride, vinyl ethyl ether, vinyl butyl ether, or vinylisobutyl ether, vinyl ether ketone, vinyl formamide, N-vinyl acetamideand the like.

d. Vinyl compounds of aromatic compounds and heterocyclic compounds,such as styrene, a-methylstyrene, vinyltoluene, p-chlorostyrene,divinylbenzene, 2-vinyl pyrrolidone and 2-vinyl pyridine.

e. N-Methylol ethers of acrylic acid amide and methacrylic acid amidehaving the formula:

1 Cllz =C-CO-NCH2O R2 in which R is hydrogen or a methyl group,

R is hydrogen or an C -C -alkyl, C -C -aralkyl or c C -aryl group,

R is an C C -alkyl or cycloalkyl group such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl or cyclohexyl groups (see US. Pat. No.2,978,432);

and unetherified N-methyl compounds of acrylic and methacrylic acidamide.

f. Mannich bases of acrylic acid amide and of methacrylic acid amidehaving the formula:

in which R and R, are as described for formula I, and R and R are C -C-alkyl or cycloalkyl groups or together represent a heterocyclic radicalsuch as the morpholine radical. Suitable compounds of this type arementioned in US. Pat. application Ser. No. 851,971, filed on Nov. 10,1959. g. Acrylic and methacrylic acid derivatives which contain aterminal halomethyl carbonyl group and have (see US. Pat. No.3,467,614). I

h. Alkyl compounds such as trisacryloyl-perhydro-striazine, triallylcyanurate, triallyl phosphate or allyl alcohol.

i. Monoolefinically unsaturated aliphatic hydrocarbons having two to sixcarbon atoms such as ethylene, propylene, hexylene, butylene,isobutylene and the like.

j. Conjugated diolefines having four to six carbon atoms, such asbutadiene, isoprene, 2,3-dimethyl butadiene, chlorobutadiene and thelike.

k. Norbornene and hydroxymethyl norbornene.

Acrylic and methacrylic acid esters having one to 12 carbon atoms in thealcohol residue, acrylonitrile, styrene, acrylic and methacrylic acidnitrile, vinyl acetate, vinyl propionate, vinyl chloride, vinylidenechloride or ethylene or propylene in combination with one or more of themonomers mentioned above are particularly advantageous.

The polymerization reaction is carried out at temperatures of from aboutto about 140 C. and preferably from about 40 to about 130 C.

Any suitable polymerization initiators which decompose into radicals maybe used in quantities of from about 0.05 to about 3 percent by weightbased on the weight of the monoor di-olefins. Some suitable initiatorsinclude peroxides such as, for example, lauroyl peroxide, cyclohexanonehydroperoxide, tertiary butyl peroctoate, tertiary butyl perpivalate,dichlorobenzoyl peroxide, benzoyl peroxide, di-tertiary butyl peroxide,tertiary butyl hydroperoxide and cumene hydroperoxide; peroxy carbonatessuch as diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonateand diisooctylperoxydicarbonate; sulphonyl peroxides such as acetylcyclohexyl sulphonyl peracetate, sulphonyl hydrazides and azo compoundssuch as azodiisobutyric acid dinitrile. Inorganic peroxides such ashydrogen peroxide, potassium peroxydisulphate and ammoniumperoxydisulphate are also suitable.

The initiators which decompose into radicals may be used alone or incombination with reducing agents or heavy metal compounds. Sodiumpyrosulphite, potassium pyrosulphite, formic acid, ascorbic acid,hydrazine derivatives, amine derivatives and Rongalite are examples ofsuch compounds. The heavy metal compounds may be present either in anoil-soluble or in a watersoluble form. Water-soluble heavy metalcompounds include, for example, silver nitrate, halides or sulphates ofdivalent or trivalent iron, cobalt or nickel or salts of titanium orvanadium of lower valency state. Examples of oil-soluble heavy metalcompounds are cobalt naphthenate and the acetylacetone complexes ofvanadium, cobalt, titanium, nickel or iron.

The polymerization is preferably carried out at pH values of from about2 to about 9.

The process of the invention is carried out under radical emulsionpolymerization conditions, this means in aqueous medium in the presenceof an oligourethane salt as emulsifier for the starting materials aswell as for the end products and of radical initiating catalysts attemperatures such that the catalyst becomes active.

Polymerization is carried out in an aqueous emulsion. According to apreferred method the olefinic monomers are mixed with the oligourethanesdescribed above and then emulsified by stirring water into the mixture.The oligourethanes act as emulsifiers so that ordinary, low speedstirrers may be used.

In another advantageous method for carrying out the polymerizationreaction the monomers are added to an aqueous sol of oligourethanes, andagain stable emulsions can be obtained using conventional low speedstirrers. The solids content of the aqueous oligourethane dispersionsused should be from about 2 to about 55 percent by weight. A solidscontent of from about 10 to about 30 percent by weight is especiallyadvantageous.

In still another embodiment 10 25 percent of the total monomers areemulsified in an aqueous so] of the oligourethane and the remainder ofthe monomers is added after polymerization has been initiated.

In yet another embodiment, an emulsion of monomers in an aqueous sol ofoligourethane salts may be added gradually to a monomer emulsion or to anuclear latex. Although the polymerization initiators may be added atany time, the operation is preferably carried out in such a way thatpolymerization starts only after the aqueous emulsion has been formed inorder to prevent an unwanted increase in viscosity in the homogeneousorganic phase. While polymerization is complete in from about 1 to about20 hours, in most cases 2 to 6 hours is sufficient.

After the reaction is complete, residual monomers or water or smallquantities of added solvents may be removed, for example bydistillation. Furthermore, the dispersions of this invention may becreamed up, for example, by using additives such as alginates.

Stable dispersions having a solids content of from about 20 percent toabout 60 percent by weight may be obtained by the process of thisinvention.

The dispersions may be blended! with dispersions of like charge, e.g.,with polyvinyl acetate dispersions or dispersions of polyethylene,polystyrene, polybutadiene, polyvinyl chloride and polymer resins.Further, fillers, plasticizers, pigments, hydrofluoric acid and silicicacid sols and dispersions of aluminum, clay, asbestos and the like maybe incorporated therein.

The dispersions of the modified vinyl polymers of this invention inwater are stable and suitable for storage and transport and can bemolded or otherwise shaped at any subsequent time. The dispersionsgenerally dry directly to form dimensionally stable synthetic resincoatings. Shaping of the products may also be carried out in thepresence of known cross-linking agents. For this purpose, polyfunctionalcross-linking substances can be added to the modified vinyl polymers atany time during the process of this invention as well as after theevaporation of any solvent present either at room temperature orelevated temperature. Some examples of such cross-linking agents includesulphur, sulphur sols, free and partially or completely maskedpolyisocyanates, carbodiimides, formaldehyde or substances which giveoff formaldehyde, methylol compounds and their ethers and organic andinorganic peroxides. The cross-linking agents which may be in the formof solutions or suspensions, fillers, pigments, blending agents andother additives may be added in the course of the process. Thedispersions of the invention remain stable even after addition of thecross-linking agent. Films prepared from the dispersions containingcross-linking agents are, however, completely water-resistant.

The aqueous dispersions of this invention may have a liquid or pastyconsistency and are stable without the addition of an emulsifier.However, suitable cationic, anionic or neutral emulsifiers andprotective colloids as well as thickeners such as casein which has beendecomposed by acid or ammoniacal decomposition, soaps, invert soaps,alkyl sulphonates, polyvinyl alcohol, ethoxylated phenols, oleylalcoh'ol polyglycol ethers, ethoxylated polypropylene glycol or naturalproducts such as gelatin, gum arabic, tragacanth or fish glue may beadded in the course of the process. Such additives serve mainly toreduce the comparatively high surface tension of the dispersionsalthough they also advantageously affect the chemical stability of thedispersions and their coagulability. Nevertheless, the addition ofemulsifiers customarily used in emulsion polymerization is by no meansnecessary in the process of the invention.

The aqueous salts or dispersions obtained by the process of thisinvention are versatile in their use. Thus, dip molded articles can beprepared or foam resins may be obtained by the latex churning process.Coagulates can also be obtained by the addition of an electrolyte to theaqueous solutions and dispersions which can be worked up on mixingrollers. By evaporating the water, non-sticky and sticky films and foilscan be obtained. The products of this invention are suitable forcoating, covering and impregnating woven and non-woven textiles,leather, paper, wood, metal, ceramic, stone, concrete, bitumen, hardfiber, straw, glass, porcelain, synthetic resins of all kinds and glassfibers. They may be employed as antistatic and crease-resistant finishesand as binders for fleeces, as adhesives, adhesifying agents, laminatingagents, agents for rendering substances hydrophobic, plasticizers orbinders, e.g., for cork powder, sawdust, glass fibers, asbestos,paper-type materials, plastics, rubber waste or ceramic materials, or asauxiliary agents in cloth printing as well as in the paper industry, asadditives for polymer dispersions and as sizes and as a finishing agentfor leather.

The invention is further illustrated but is not intended to be limitedby the following examples in which all parts and percentages are byweight unless otherwise specified.

EXAMPLES Starting materials Oligourethane 1:

About 580 parts (0.333 mol) of a polyester of adipic acid,hexane-1,6-diol and 2,3dimethylpropane- 1,3-dio1 (HN), molar ratio30:22:12

About 79 parts (0.667 mol) of N-methyldiethanolamine (MDE) About 236parts (1.400 mol) of hexane-1,6-diisocyanate About 93 parts (0.800 mol)of 3-ethyl-3-hydroxymethyl-oxetane About 58 parts of per cent phosphoricacid About 2,200 parts of water HN, MDE and ml of glycol monomethylether acetate are heated to about 70 C. The diisocyanate is addeddropwise in about 5 minutes and after the exothermic reaction thetemperature is maintained at about to C. for 20 minutes. The reactionmixture is then cooled to about 95 C. and the oxetane is added followed10 minutes later by the addition of the phosphoric acid in about 200parts of water and then about 2,000 parts of water are added. Thereaction mixture is then stirred for one hour at about 80 C. and cooledto room temperature.

An opaque so] which has a solids content of about 32 percent isobtained. pH 5, particle size l. The molecular weight of theOligourethane salt is approximately 2,500.

An air-dried foil prepared from the opaque sol treated at about 120 C.for about 20 minutes has a tensile strength of less than 1 kg wt/cm". Itis clear, waxy and sticky.

Oligourethane 2:

About 580 parts (0.333 mol) of a polyester of adipic acid,hexane-l,6diol and 2,2-dimethylpropane- 1,3-diol (HN), molar ratio30:22:12

About 80.5 parts (0.500 mol) of 2-dimethylamino-2- ethylpropanel ,3-diol(DTPE) About 196 parts (1.170 mol) of hexane-1,6-diisocyanate About 78parts (0.670 mol) of 3-ethyl-3-hydroxymethyl-oxetane About 37 parts of85 per cent phosphoric acid About 2,200 parts of water.

The method is analogous to that employed for Oligourethane 1. An opaquesol which has a solids content of about 27.8 per cent is obtained. pH 5,particle size 1. The molecular weight of the Oligourethane salt isapproximately 2,800.

A clear foil prepared from the opaque $01 which has been afterheated atabout 120 C. for about 20 minutes is waxy and sticky. It has a tensilestrength of less than 1 kg wt/cm Oligourethane 3:

About 500 parts (0.295 mol) of a polyester of adipic acid,hexane-1,6-diol and 2,2-dimethylpropane- 1,3-diol (HN), molar ratio30:22:12

About 41 parts (0.254 mol) of 2-dimethylamino-2- ethylpropane-l ,3-diol(DTPE) About 33 parts (0.555 mol) ofurea About parts (0.830 mol) ofhexane- 1 ,6-diisocyanate About 18 parts of 85 per cent phosphoric acidAbout 1,100 parts of water.

HN, DTPE and urea are heated to about 75 C. The isocyanate is addeddropwise in about 2 minutes and the reaction mixture is heated to about135 C. The temperature is maintained at about 135 C. for about 30minutes. About 100 m1 of glycol monomethyl ether acetate are added toreduce the viscosity and the reac tion mixture is cooled to about 1 10C. The phosphoric acid is added in about 200 parts of water and afurther about 900 parts of water are added dropwise at about 75 C.within about 1 hour.

An opaque sol which has a solids content of about 40.4 percent isobtained. pH 4.5, particle size 1. Molecular weight approximately 2,600.A foil produced as described for oligourethane 1 is clear and sticky andhas a tensile strength of less than about 2 kg wt/cm oligourethane 4:

About 475 parts (0.500 mol) of propoxylated 2-dimethylaminomethyl-Z-ethyl propanei ,3-diol, m. w. 950 (PE) About 1 18parts (0.700 mol) of hexane-1 ,6-diisocyanate About 27 parts (0.450 mol)of urea About 38 parts of 85 percent phosphoric acid About 45 ml of 30percent formalin About 1,400 parts of water.

PE and urea are heated to about 75 C. and the isocyanate is addeddropwise in about 2 minutes. The temperature is raised to about 135 C.and maintained at this level for about 1 hour. The viscosity is reducedwith about 30 ml of glycol monomethyl'ether acetate and the reactionmixture is cooled to about 1 10 C. The phosphoric acid is added in about200 parts of water followed by the addition of a further about 500 partsof water. The formalin and the remainder of the water are then addeddropwise at about 90 C. and the reaction mixture is cooled to roomtemperature.

An opaque sol is obtained. pH 5, particle size 2, solids content 31 percent, molecular weight of the oligourethane approximately 6,000. The soldries to form a clear, self-supporting foil which has a tensile strengthof less than 20 kg wt/cm.

Oligourethane 5:

The composition and method of preparation are as described foroligourethane 4 except that only about 34 parts of 85 percent phosphoricacid are used.

An opaque sol is obtained. pH 5, particle size 2, solids content 31.5percent. The sol dries to form a self-supporting, clear foil which has atensile strength of less than kg wt/cm oligourethane 6:

About 237 parts (0.10 mol) of a polyester of adipic acid and diethyleneglycol, molar ratio 1:1 .2

About 34 parts (0.20 mol) of hexane-1,6-diisocyanate About 144 parts(0.20 moi) of sodium taurinate as a percent solution in water About 14parts (025 mol) of potassium hydroxide About 32 parts (0.20 moi) ofmaleic acid ureide About 950 parts of water The diisocyanate is added tothe polyester at about 80 C. and the reaction mixture is heated to about120 to about 125 C. and maintained at this temperature for about 2 hoursafter which it is cooled to about 90 C. The solution of sodiumtaurinate, potassium hydroxide and maleic acid ureide are added all atonce. After about 15 minutes the water heated to about 90 C. is addeddropwise at this temperature in the course of from about 20 to about 50minutes. An opaque sol which has a solids content of about 2.56 per centis obtained. pH 8, particle size 1. An air-dried, self-supporting foilprepared from the opaque sol is clear and non-sticky and has a tensilestrength of less than 1 kg wtlcm The molecular weight of theoligourethane salt is approximately 5,000. Oligourethane 7:

About 356 parts (0.15 mol) of a polyester of adipic acid and diethyleneglycol, molar ratio 1: 1.2 About 42 parts (0.25 mol) ofhexane-1,6-diisocyanate About 144 parts (0.20 mol) of sodium taurinateas a 20 percent solution in water About 14 parts (0.25 mol) of potassiumhydroxide About 32 parts (0.20 mol) of maleic acid ureide About 600parts of water. A white dispersion having a solids content of 37.2 percent is obtained by the reaction carried out as described foroligourethane 6 pH 1.5, particle size 2 to 3. A clear, non-sticky foilhaving a tensile strength of less than 5 kg wt/cm is obtained from thedispersion. The molecular weight of the oligourethane saltisapproximately 7,000.

oligourethane 8:

An oligourethane analogous to oligourethane 4 is obtained from:

About 260 parts (0.125 mol) of propoxylated 2-dimethylaminomethyLZ-ethylpropanel ,3-diol, m. w. 2,080

About 29 parts (0.175 mol) of hexane-l,6-diisocyanate About 7 parts (0.116 mol) ofurea About 10 parts of 85 per cent phosphoric acid and About900 parts of water in the form of an optically clear sol; pH 4.5, solidscontent 25.3 percent. The molecular weight of the oligourethane isapproximately 5,000. The sol dries to form a clear, sticky foil whichhas a tensile strength of less than 5 kg wt/cm Oligourethane 9:

An optically clear sol, pH 5, solids content 25 percent, molecularweight approximately 5,000, is obtained in a manner analogous tooligourethane 4 from:

About 260 parts (0.125 mol) of propoxylated 2-dirnethylaminomethyl-2-ethylpropane-l ,3-diol, m. w. 2,080,

About 31.5 parts (0.175 mol) of l-methyl-2,4-diisocyanato-cyclohexane(isomeric mixture :20),

About 7 parts of urea,

About 10 parts of per cent phosphoric acid and About 900 parts of water.

The properties of the foil are similar to those of oligourethane 8.

Oligourethane 10:

An optically clear sol, pH 4.5, solids content 25.6 percent, molecularweight approximately 5,000, is obtained in a manner analogous tooligourethane 4 from:

About 260 parts (0.125 mol) of propoxylated 2-dimethylaminomethyl-2-ethylpropanel ,3-diol, m. w. 2,080,

About 39 parts (0.175 mol) of isophorone diisocyanate,

About 7 parts of urea,

About 10 parts of 85 percent phosphoric acid and About 900 parts ofwater.

The properties of the foil are similar to those of oligourethane 8.

Oligourethane 11:

An optically clear sol, pH 5, solids content 23.5 per cent, molecularweight approximately 5,000, is obtained in a manner analogous tooligourethane 10 but using about 30.4 parts (0.175 mol) of .tolylenediisocyanate (isomeric mixture 65:35). The properties of the foil aresimilar to those of oligourethane 8. oligourethane 12:

An optically clear sol, pH 4, solids content 19.6 percent, molecularweight approximately 5,000, is obtained in a manner analogous tooligourethane 10 from about 245 parts (0.250 mol) of propoxylated 2-dimethylaminomethyl-2-ethylpropane-1,3-diol, m. w. 980, about 59 parts(0.350 mol) of hexane-1,6-diisocyanate, about 13.5 parts of urea, about38 parts of 85 percent phosphoric acid, about 45 parts of 30 percentformalin and about 1,400 parts of water. An air-dried film prepared fromthe sol and heated to about 130 C. for about 20 minutes is clear andnon-sticky but has a tensile strength of less than 20 kg/cmOligourethane 13:

1f about 25 parts of 85 percent phosphoric acid and only about 700 partsof water are used in the method described for oligourethane 12, anoptically clear sol having a pH 5, solids content 32.8 percent andmolecular weight approximately 5,000 is obtained. The properties of thefilm are similar to those of oligourethane 12.

Oligourethane 14:

About 490 parts (0.500 mol) of propoxylated methyl diisopropanolamine,m. w. 980,

About 1 18 parts (0.700 mol) of hexane-1,6-diisocyanate,

About 27 parts of urea,

About 50 parts of 85 per cent phosphoric acid,

About 90 parts of 30 percent formalin and About 1,400 parts of water.

By a method analogous to that employed for oligourethane 4, an opticallyclear sol, pH 5, solids content 35.8 per cent, molecular weight=approximately 5,000 is obtained. The properties of the film are similarto those of oligourethane l2.

EXAMPLE 1 About 50 parts of water are added to about 470 parts of theso] of oligourethane 1 with stirring and about 150 parts of vinylacetate are then added dropwise. The apparatus is then carefully washedwith pure nitrogen and Using two dropping funnels, about 40 parts ofabout a 3 percent aqueous potassium peroxydisulphate solution and about40 parts of about a 0.3 percent aqueous sodium pyrosulphite solution ascatalyst solutions are simultaneously added dropwise in the course ofabout one hour. Polymerization starts immediately; the temperature risesto from about 70 to about 75 C. After the addition of these twosubstances, the temperature is maintained at about 65 C. for a further 4hours and the reaction mixture is then cooled to room temperature.

Yield: 745 g.

Properties of the dispersion:

particle size 2 solids content 40 per cent viscosity Ford-Becher/D 4:16.8".

Properties of film:

Clear, relatively elastic film of high tensile strength.

EXAMPLES 2 TO 18 cent of the theoretical yields.

EXAMPLE 19 About 100 parts of 20 percent oligourethane 6 and 20 parts ofethyl acrylate are mixed in a mineral water bottle. The bottle iscarefully washed with pure nitrogen, closed with a serum cap andperforated crown cork, and about 6 parts of each of the catalystsolutions mentioned in Example 1 are injected. The contents of thebottle are thoroughly shaken, a slight excess pressure of nitrogen isproduced, and the bottle is kept in a roller box at about C for about 5hours. The cooled dispersion has the following properties:

particle size l solids content= 30. l per cent viscosity Ford-Becher/D4: 10.4"

Yield: approximately 130 g Properties of film:

Clear, soft film with good tensile strength and pleasant hand.

EXAMPLES 20 to 23 The method is the same as that of Example 19. The 1corresponding data are found in Table 1. The yields of dispersion are to99 percent of the theoretical.

EXAMPLES 24 TO 28 heated to about 65 C. under a stream of nitrogen. 55Table 1.

TABLE 1 Catalyst Viscosity KzSzOa N82S2O DH Ford- Solids Quantity 3 3Particle 01 the Solids Becher Ol1go content of sol Water aqueous aqueousQuantity size dispcrcontent nozzle 4 Example urethane (percent) used(g.) (g.) solution solution Monomer (15-) 01' l). sion (percent) (500-)1 32. 0 470 270 10 40 VA 300 1-2 5 3i). 4 l4. 7 1 32.0 470 161) 40 '10 EA 150 l 5 35. 4 l3. 4 1 32. 0 470 100 40 40 VA 100 l 5 33. 'J 12. K 132, 0 470 100 10 40 lCA-I-S'l(l l) l .2 5 35. 0 13. 0 2 27. 8 550 350 4040 V A 150 l 5 ill. 7 ll. 5 2 27.8 550 350 40 Ml VA 300 l 3 5 33.0 13.03 40. 4 400 501) 50 50 EA l i! 5 2(1. 0 11.0 3 40.4 400 5110 511 fill VA1130 l .3 1.5 25.3 11.1] 4 31.0 400 100 51! {ill VA 130 l 5 2811 12.8

Table l ontimlctl Catalyst Viscosit mszot. Nm zm. pII Ford SolidsQuantity 3% 3% Particle of the Solids Becher Oligocontent of sol Wateraqueous aqueous ,Qnantity size rlispercontent nozzle 4 Example urethane(percent) used (g.) (g.) solution solution Monomer (g.) of I). 51011(percent) (see) 4 31. 50 50 VA 525 4 42. 3 21.0 4 31.0 50 50 VA 210 3-45 30. 3 12. 5 5 31. 5 5O 50 EA 150 2 5 25. 0 12. U 5 31. 5 50 50 EA 1502 5 24. Z 11, 3 5 31. 5 5t) 50 ST 128 2 5 25.0 11. 6 6 35. 2 40 40 ST150 1-2 7 33. 6 11. 2 6 25. 6 40 40 ST+BA(1:1) 150 2 7. 5 31. 2 13, 0 625. 6 40 40 BA 150 2 7. 5 31. 4 12. 2 6 20. 0 6 6 BA 1 7. 5 31. El 10. 46 20.0 6 6 ST 20 1-2 7. 5 32. 0 11. 3 6 20.0 G 6 VA 20 2 4. 5 .26. .l17. 5 6 20.0 6 0 EA 2|) 1 7. 5 32. U 11. 3 8 25. 3 25 VA 50 2 -l 22. 311. 5 9 25. 0 10 10 VA 10 1 -l. 5 18. 6 1]. I) 10 25.6 10 10 VA 50 l 4.5 1!). I 12.x 1] 23. 5 400 VA 200 Z 4. 5 30. l 12. 2 12 10. 5 25 25 VA50 1 3 21. (l 11 7 VA=vinyl acetate; EA=ethy1 acrylate; SI=styrene;BA=butyl acrylatc. (a) Partitclle sixe, qualitative: 1 opaque andtransparent, approximately 50 ma 4:; 2 to 5 particle size between a andii; ti milky white dispersion approxima e y [1 o.

X Polymerization was released by the addition of 2 g. ofazodiisobutyrit' acid nitrilo.

TABLE 2 Properties of film: Properties of film Thgrittlzlsggslon dnes toform a clear, non-sticky but Example a 25 1 clear, relatively hard filmsof low elasticity and high EXAMPLE tensile strength About 500 parts ofoligourethane sol 2 are in troduced into an autoclave and a solution ofabout 375 parts of water and about 1 part of potassium persulphate isstirred in. After the air has been displaced with nitrogen, about 26parts of vinyl chloride and about 149 parts of vinylidene chloride areforced in. The reaction mixture is then heated at about 50C. for about 5hours and thereafter at about 60C. for about 5 5 hours. The dispersionhas a solids content of about 28.5

percent and on drying yields a clear, elastic film.

2 relatively hard, clear film of high tensile strength 3 soft, clear,highly elastic film 4 soft, elastic film of relatively low tensilestrength 30 5 opaque, hard and brittle film 6 clear and soft film, lowtensile strength 7 clear film of high tensile strength 8 clear, softfilm 9 clear, soft film of moderate tensile strength 10 clear, elasticand soft film of high tensile strength 1 1 clear, elastic and soft filmof high tensile strength 12 clear, relatively hard film of excellenttensile EXAMPLE 31 strength 13 clear, elastic and soft film Using themethod described in. Example 30, about 14 clear, elastic and soft film500 parts of water and about 3 parts of potassium perl5 opaque,inelastic, relatively hard film sulphate are added to about 1,000 partsof oligoul6 opaque, brittle and hard film rethane 2 and dispersedtogether with about 270 parts 17 opaque film of relatively low tensilestrength of vinyl chloride in a pressure vessel under nitrogen. 18clear, soft and elastic film The reaction mixture is heated to about55C. and 19 clear, soft film of good tensile strength polymerized atthat temperature for about 10 hours. 20 clear, soft film The autoclavecontent is homogeneous. The dispersion 21 paq i e y hard and brittlefilm dries to form a clear film which has a chlorine content 22 clear,soft film of 25.3 per cent, corresponding to a polyvinyl chloride 23clear, soft film with relatively good tensile te t f 45 percent,

strength 24-28 clear, non-sticky films with good tensile EXAMPLE 32Strength The previous example is repeated except that the reactionmixture is saturated with 30 atmospheres of EXAMPLE 29 ethylene at roomtemperature. The stable dispersion About 500 parts of oligourethane 2are introduced yields a clear, elastic film when dried in air at roomunder nitrogen into a flask equipped with stirrer, and a mperature.

solution of about 1.3 parts of potassium persulphate in EXAMPLE 33 about300 parts of desalted water lS stirred in. About 150 parts of vinylidenechloride are then dispersed in E P 31 repated g about 270 p j of P thecontents of the flask, the reaction mixture is heated tad lene F of W Astable dlsperslon to the fl temperature and polymerization is which duesin air to form aclear film is obtained.

itiated by the dropwise addition of about 0.3 part of sodiumpyrosulphite in about 100 parts of water. The EXAMPLE 34 temperature isthen kept at about 60 C. for about 5 About 500 Parts of aqueousOligourethane 2 are hours. diluted with about 175 parts of water undernitrogen in Yield: 1040 g Properties of dispersion: a vessel equippedwith a stirrer and about parts of a Solids content 25.4 percent, pH 5,mixture of about 50 parts of styrene, about 5 parts of particle size 1.acrylic acid, about 10 parts of oxypropyl methacrylate,

about 10 parts of acrylamide-N-methylol methyl ether and about 25 patsof butyl acrylate are dispersed therein. The reaction mixture ispolymerized under nitrogen at about 60C. by dropwise addition of asolution of about 0.5 percent (based on the monomer mixture) ofpotassium peroxydisulphate in about 50 parts of water and about 0.05percent of sodium pyrosulphite in about 50 parts of water in the courseof about 6 hours. When dry, the dispersion (solids content 29 percent)yields a clear film which, after being heated to about 180C. (30minutes), is insoluble in the usual solvents.

EXAMPLE 35 About 113 parts of hexane-1,6-diisocyanate are added at about83C. to about 500 parts of a polyester of adipic acid, hexanediol andneopentyl glycol (molar ratio 30:22:12, molecular weight 1740) and about36 parts of N-butyldiethanolamine. The temperature rises to about 136C.within about 6 minutes. After about 30 minutes stirring at about 131 toabout 144C., about 19 parts of urea are added. The molecular weight ofthe oligourethane before polymerization is approximately 5,000. After afurther about 30 minutes stirring at about 130 to about 140C, thefollowing are added successively: a solution of about 18 parts of 85percent phosphoric acid in about 100 parts of water at about 95C in thecourse of about 9 minutes, about 70 parts of butyl acrylate in thecourse of about 4 minutes and about 1,000 parts of water at about 90C.in the course of about 30 minutes. Polymerization is then initiated bysimultaneously adding about 20 parts of a3 percent potassium persulphatesolution and about 20 parts of a 0.3 percent sodium pyrosulphitesolution dropwise to the resulting dispersion at about 80C. The reactionmixture is then stirred for about 2 hours at about 80C., and about 100parts of a 30 percent aqueous formaldehyde solution are added.

A white, coarse latex is obtained which has a solids content of 35percent.

Drying at room temperature and after-heating at about 120C. yields asoft, transparent and elastic foil which has very good resistance tohydrolysis.

EXAMPLE 36 About 474 parts of a polyester of adipic acid and diethyleneglycol (molar ratio 1:1.2; molecular weight 2,300) and about 67 parts ofhexamethylene-l,6-diisocyanate are stirred for about 2 hours at about117 to about 129C. About 70 parts of methyl acrylate and a solution ofabout 288 parts of a 20 percent sodium taurinate solution, about 28parts of potassium hydroxide and about 64 parts of maleic acidmonoureide in about 100 parts of water which has been prepared about 20minutes previously are added successively to the melt which has beencooled to about 81C. About 20 minutes later, the following are addedsuccessively: about 1 part of benzoyl peroxide in about 5 cc of acetone,about 1,500 cc of water at about 70C. and about 0.1 part of dimethylaniline in about 2 cc of acetone (polymerization starter).Polymerization is finished after about 3 hours stirring at about 70C.About 100 parts of 30 percent formalin and about 200 parts of 20 percentphosphoric acid are added to the resulting dispersion. An opaque, highlyfluid sol is obtained which has a solids content of 32 percent.

EXAMPLE 37 The procedure is the same as in Example 36 but about parts ofacrylonitrile are added instead of methyl acrylate. An opaque, highlyfluid sol is obtained which has a solids content of 32 percent.

EXAMPLE 38 About 500 parts of polypropylene ether glycol of molecularweight 2,000 and about 133 parts of tolylene diisocyanate (isomericmixture 65:35) are stirred for about 30 minutes at about to about C.About 21 parts of urea are then added, the reaction mixture is heated toabout 135C. in the course of about 17 minutes and then cooled to about70C. in the course of about 30 minutes. About 40 parts ofN-methyldiethanolamine are added, the reaction mixture is stirred forabout one hour at about 70C. and the following are then addedsuccessively: about 100 parts of vinyl acetate, a solution of about 30parts of 85 percent phosphoric acid in about 100 parts of water, about 1part of benzoyl peroxide in about 9 parts of acetone, about 1,900 partsof water (70C) and about 0. 1 part of dimethyl aniline in about 2 partsof acetone. Polymerization is carried out for about 5 hours at about70C. About 50 parts of 30 percent aqueous formaldehyde are then added. Afinely divided, thick 22 percent sol which dries at room temperature toform a soft elastic foil is obtained.

It is to be understood that any of the components and conditionsmentioned as suitable herein can be substituted for its counterpart inthe foregoing examples and that although the invention has beendescribed in considerable detail in the foregoing, such detail is solelyfor the purpose of illustration. Variations can be made in the inventionby those skilled in the art without departing from the spirit and scopeof the invention except as is set forth in the claims.

What is claimed is:

l. A process for the production of stable aqueous polymer dispersionswhich comprises polymerizing from about 5 to about percent by weight ofat least one polymerizable olefinically unsaturated monomer under freeradical forming conditions in the presence of from about 5 to about 95percent by weight of an oligourethane salt having a tensile strength ofless than about 20 kg wt/cm a salt group content of 10 to 400milliequivalents percent based on grams of the salt and prepared byreacting an organic polyisocyanate with an organic compound having atleast two groups reactive with NCO groups.

2. The process of claim 1 wherein the oligourethane salt is in the formof an aqueous sol.

3. The process of claim 2 wherein the aqueous sol has a solids contentof from about 2 to about 55 percent by weight.

4. The process of claim 1 wherein the oligourethane salt has a tensilestrength of less than about 5 kg wt/cm 5. The process of claim 1 whereinthe oligourethane salt is a cationic compound containing at least one 6.The process of claim 1 wherein the oligourethane salt is an anioniccompound containing at least one .COO", -SO -OSO -SO radical in which Ris alkyl, cycloalkyl, aralkyl or aryl.

7. The process of claim 1 wherein l 25 percent of the monomers areemulsified in an aqueous sol of the oligourethane and the remainder ofthe monomers is added after polymerization has been initiated.

8. The process of claim 1 wherein a stable emulsion of the monomers inan oligourethane sol is added to the polymerization mixture.

9. The process of claim 1 wherein water is added and stirred into amixture of the oligourethane salt and one or more olefinic monomers toform a dispersion and polymerization is then initiated.

10. The process of claim 1 wherein the oligourethane salt is prepared byreacting water insoluble compounds which contain terminal hydroxylgroups and which have a molecular weight of from about 400 to about5,000 with an organic polyisocyanate at a temperature of from about 20Cto about 160C.

11. The process of claim 10 wherein the NCO/OH ratio is from about 0.4to about 0.9 or from about 1.1 to about 2.

12. The process of claim 1 wherein the oligourethane has a viscosity ofless than about l,500 poises at about 120C.

13. The process of claim 1 wherein the monomer is polymerized at atemperature of from about 0 to about l40C.

14. The process of claim 1 wherein the polymerization is carried out inthe presence of from about 0.05 to about 3 percent by weight based onthe weight of the olefin of a polymerization initiator.

15. The process of claim 1 wherein the polymerization is carried out ata pH of from about 2 to about 9.

16. A stable aqueous dispersion prepared by the process of claim 1containing 5 to '95 percent by weight of oligourethane salts having anaverage molecular weight of 1500 to 20,000 and a tensile strength ofless than 20 kg wt/cm which salts have been prepared from waterinsoluble oligohydroxy compounds having a molecular weight of 400 to5,000, and 5 to percent by weight of at least one polymerizableolefinically unsaturated monomer.

17. The stable aqueous dispersion of claim 16 having a solids content offrom about 20 to about 60 percent by weight.

2. The process of claim 1 wherein the oligourethane salt is in the formof an aqueous sol.
 3. The process of claim 2 wherein the aqueous sol hasa solids content of from about 2 to about 55 percent by weight.
 4. Theprocess of claim 1 wherein the oligourethane salt has a tensile strengthof less than about 5 kg wt/cm2.
 5. The process of claim 1 wherein theoligourethane salt is a cationic compound containing at least one
 6. Theprocess of claim 1 wherein the oligourethane salt is an anionic compoundcontaining at least one -COO( ), -SO3( ), -O-SO3( ), -SO2( ) radical inwhich R is alkyl, cycloalkyl, aralkyl or aryl.
 7. The process of claim 1wherein 10 - 25 percent of the monomers are emulsified in an aqueous solof the oligourethane and the remainder of the monomers is added afterpolymerization has been initiated.
 8. The process of claim 1 wherein astable emulsion of the monomers in an oligourethane sol is added to thepolymerization mixture.
 9. The process of claim 1 wherein water is addedand stirred into a mixture of the oligourethane salt and one or moreolefinic monomers to form a dispersion and polymerization is theninitiated.
 10. The process of claim 1 wherein the oligourethane salt isprepared by reacting water insoluble compounds which contain terminalhydroxyl groups and which have a molecular weight of from about 400 toabout 5,000 with an organic polyisocyanate at a temperature of fromabout 20*C to about 160*C.
 11. The process of claim 10 wherein theNCO/OH ratio is from about 0.4 to about 0.9 or from about 1.1 to about2.
 12. The process of claim 1 wherein the oligourethane has a viscosityof less than about 1,500 poises at about 120*C.
 13. The process of claim1 wherein the monomer is polymerized at a temperature of from about 0*to about 140*C.
 14. The process of claim 1 wherein the polymerization iscarried out in the presence of from about 0.05 to about 3 percent byweight based on the weight of the olefin of a polymerization initiator.15. The process of claim 1 wherein the polymerization is carried out ata pH of from about 2 to about
 9. 16. A stable aqueous dispersionprepared by the process of claim 1 containing 5 to 95 percent by weightof oligourethane salts having an average molecular weight of 1500 to20,000 and a tensile strength of less than 20 kg wt/cm2, which saltshave been prepared from water insoluble oligohydroxy compounds having amolecular weight of 400 to 5,000, and 5 to 95 percent by weight of atleast one polymerizable olefinically unsaturated monomer.
 17. The stableaqueous dispersion of claim 16 having a solids content of from about 20to about 60 percent by weight.